Here's a video on using roving to make felt sheets: https://www.youtube.com/watch?v=jNMs2LSXq70
handy for things but I suspect not for making a hat - unless you really wanna make yarn out of it. I was gonna try to make a hat out of it but was clued in by the good people here that knitting (with already made yarn lol) and then felting is the way to go. Same principles here though - turning wool into felt - just for different applications.